Milk is a liquid that comes from the mammary glands of mammals. Other things which people sometimes call milk are usually not milk at all - rice milk, soy milk, potato milk, almond milk. These are actually liquids based on plant sources which people like to call milk because it seems to go over better psychologically than something called 'Plant-liquid-whitish-colored-sweetened-beverage-substance'.

Milk is a highly studied compound due to its basic nutrition which baby mammals thrive on (including humans). There is extensive science from the dairy and cheese making industries as well. see Animal Science Research

Milk consists of a variety of proteins, vitamins, minerals, other nutritious substances, and things simply called growth factors. One category of proteins is called casein. There are a variety of casein proteins in milk (not just one type), and this is the main protein in cheese. If you take all the casein out of milk, what you have left is called whey. Whey contains the milk sugar lactose. Special proteases are protein-breaking enzymes needed to break down the milk protein casein. Lactase is a sugar-breaking enzyme that breaks down the milk sugar lactose. Both of these needed enzymes originate from the mucosal lining in the intestine (although some proteases come from the pancreas but can only break down some of the casein bonds).

Dairy and Phenols/salicylates

I looked up the some things on the milk question raised earlier. Phenols are a chemical group that can be any of thousands of different compounds. Salicylates are one type of phenol.

[Note: one of the reasons that No-Fenol may work is that it removes the carboxyl group and allows the compound to be processed out natually. This may contribute to why it seems to work better on phenols/salicylates in foods versus artificial ingredients. More research is needed though.]

The Feingold material says that dairy/milk is no-salicylate or incredibly low in salicylates...so it is correct that dairy is not a concern as far as salicylates go. However, some milk may be high in phenols because many milks contain vitamin A palmitate. (I couldn't find anything that says raw dairy contains phenolic compounds in its composition or structure).This vitamin A may be preserved with a phenolic preservative. So dairy may be highly phenolic due to this preservative. And is what may cause the red ears, night waking, and other adverse 'phenolic' reactions when someone who is sensitive to phenols or salicylates.

There are milks on the shelves that do not contain vitamin A palmitate. Most whole milks do not have it, or there are a few brands that do not use it in skim and low fat milks, but this varies by region. Whole milk contains vitamin A naturally so that is why it is not added. The skim and low-fat processing removes part of the fat (vitamins A and D are fat-soluble) and those vitamins must be added in to meet federal guidelines. Many dairy products like cheese, yogurt, cream cheese, etc, may not contain this preservative. This is one reason you may see less adverse reactions with those products than with liquid milk. You may want to try a whole milk without palmitate and see if the reactions go away. Many people who switch to Feingold approved dairy products find they no longer have a problem with dairy. It was actually the preservatives and artificial additives that were causing the problem and not the dairy itself.

This is one of the services that the Feingold Assocation checks into. A company can label a product that way because the milk person only added milk and vitamin palmitate (considered natural)...so THEY did not add anything artificial...but the company that supplied the vitamin A did add something artificial - the phenolic preservative to keep the vitamin A from breaking down. So label reading only gets your so far.

Histamine

Dairy can provoke more histamine in the body. So someone may not have a true allergy, yet still feel uncomfortable after eating histamine-containing, or histamine-provoking foods. If they have a weakened or stressed immune system, or have an already high level of internal histamine, that person may not 'tolerate' dairy. This may be the case if dairy is tolerated some of the time but not at other times. The histamine may be trigger due to dairy itself or an adverse reaction to a preservative or other artificial additive. Using epsom salts may help here, as well as reducing any chemical additives in the diet. Reducing these other chemicals may reduce the total histamine load in the body, and then regular foods cease being a problem and good nutrition can be gained from them. see Epsom Salts
see Feingold/Failsafe Programs
see Histamine and Amine Intolerances

Allergy

A person may just have a true allergy to dairy due to any of the numerous proteins or other substances in dairy. This may be detected as an IgE mediated reaction, seen as a histamine type response, or something else. Reducing other histamine triggers may help, but it could be that someone is simply allergic to dairy and needs to avoid it all the time.

Dairy and Lactose (milk sugar)

Another reason liquid milk may cause more adverse reactions in some people than other dairy products is because it contains more lactose. Many dairy products are low or have no lactose in them, such as cheese or true yogurt, whereas the liquid milk does. Anyone with any type of gut injury may be not producing the enzyme lactase. Lactose comes from the gut lining. Anything that disrupts the gut lining (inflammation, yeast, leaky gut, etc) may disrupt the production and release of lactase into the intestines. Then there is no enzyme to break down the lactose sugar properly...and you get an adverse reaction.

Also, if you have bacteria or yeast issues, the lactose sugar can be used by these organisms, so you may see a 'yeast' or bacteria overgrowth reaction. Common chemicals produced by these organisms are histamine and alcohols...and these may produce a response very similar to the 'phenol' reactions. Both phenol reactions and yeast/bacteria involve the body trying to deal with something it sees as toxins - a detox reaction.

If you are wondering if you have lactose intolerance as opposed to some other problem with dairy, you may want to try one of the specific enzyme products for dairy sold in many grocery stores or health food stores. Or you may want to try one of the lactose-free special milks available.

Lack of Probiotics

Probiotics are the beneficial bacteria in the gut. One of the thinks probiotics do is add digestive enzymes into the mix. Lactase is one of these enzymes as well as some enzymes that breakdown milk proteins. If there is a lack of good bacteria for any reason, then you could end up with an intolerance to dairy because of insufficient milk sugar or milk protein degrading enzymes. A lack of probiotics can be cause by several reasons including an overabundance of adverse bacteria or yeast, inflammation, gut injury, poor diet, illness, and poor elimination. So the solution may be that more probiotics are needed and proper gut flora restored instead of food elimination.

Dairy and the SCD

There is a concern among some that would like to follow the Specific Carbohydrate Diet (SCD) and are hesistant to consider the yogurt and cheese recommended on SCD. Here are some thoughts.

The SCD allows certain dairy products. One is a specially made yogurt. Yogurt made this way allows time for it to 'ferment' which breaks down all of the lactose. Thus, there is no milk sugar to upset the stomach, the intestines, or feed any yeast/bacteria which may be lurking in the the gut.

One thing I have been looking at is the enzymes produced by the lactic acid bacteria in yogurt and fermented cheeses. Experience shows that people doing the Specific Carbohydrate Diet and having an autism condition consume the special yogurt and cheese without supplemental enzymes and they don't have a problem. First, not everyone with a such a spectrum condition has a problem with casein or gluten to begin with, so that may be part of it. But there are a number of families now doing SCD that used to do a casein-free, gluten-free diet (GFCF) and saw some improvement with GFCF. This would lead one to think, "Oh, if there was improvement with GFCF, then that person has a problem digesting casein and gluten." However, these families quit GFCF, started SCD (without extra enzymes and including the certain SCD dairy products) and now the child is doing fabulous.

I was wondering if somehow the casein is all broken down in the fermenting process so that it isn't a problem. While looking on Pubmed and some other sources of research, there are so many references to lactic acid bacteria breaking down casein, it was hard to know what to pull out. It is well-known in the cheese making industry. DPP IV is the identified enzyme to break certain bonds in casein. I looked up the possibility of lactic acid bacteria producing the particular enzyme DPP IV or other enzymes that might be known to break down casein. DPP IV and a few other specific proteases are in several enzymes products on the market.

Yep. There is was. One of the aminopeptidases produced by lactic acid bacteria is a prolyl dipeptidyl dipeptidase. There are other proline breaking enzymes produced by bacteria as well. Lactobacillus and Lactococcus and thermopolis and bulgaris and a bunch of other
ones too. (I could post several yards worth of pubmed abstracts if someone really wants to go through it. Later I will collect some of these and post a link for reference.)

So what is the practical application of this?

It seems that if someone is doing SCD, adds the special dairy products, has no problem with it, they should just be quite happy and go on without worrying about the casein. There is much research showing that 'good' bacteria in certain dairy foods are quite capable of 'digesting' all the casein to the extent it isn't a problem. And this means that if you are consuming those foods, you may not really need another separate enzyme product to break down casein. Plus you get the good probiotics and other beneficial components in dairy (like lactoferrin, components that fight bad bacteria, calcium, nutrients, etc). We will keep notes on this to see if the casein ever turns out to be a problem for those with an autism condition and doing SCD. If not, that point becomes irrelevant and extra enzymes targeting this problem may not be necessary.

My suggestion with SCD (for what it is worth, LOL) would be to add the yogurt/cheese when possible and then only if you do not get good results and think an enzyme product just for casein would be helpful, consider adding one. A good all-purpose enzyme product like the Digest Gold from Enzymedica or Ultra-Zyme Plus from Thropps Nutrition may still be helpful, just you wouldn't need a specific casein product (gluten would be eliminated per the diet anyway, and the proteases in general enzyme products would break down meats). Both of these products are approved for SCD.

Most enzyme products are acceptable for SCD as long as they do not contain herbs or ingredients that are not acceptable on SCD. Rice bran as a filler in enzymes products IS acceptable and approved by the originator of SCD. The part of the rice bran used in this way is mainly the oil, not the starch.

Beneficial Properties of Casein Peptides

Some people may have difficulty digestion casein, or a derivative of a casein protein. Allergies are possible with any protein. However, the problem may be one of insufficient digestion and not that of an adverse reaction to the protein itself. If the poor digestion is addressed, then the root problem is solved and casein is no longer a problem.

One effective method of dealing with insufficiently digested casein is with an enzyme product targeting this protein. The breaks down the peptide and there is no more problem. Another possibility is by taking steps to heal an injured gut. Enzymes can help heal the gut in a number of ways and may be a very effective measure to consider right away.see Leaky Gut

Are casein peptides always harmful? Apparently not. They are often the basis of very nutritious foods. I have spent hours on the pubmed research site and in conversation with some researchers today. Surprise, surprise. Of hundreds of similar studies, here are a few. The first two show that there are an assortment of peptides derived from casein, of which only some are opiate peptides. These assorted peptides are seen to have very many beneficial and healthful properties. Note the dates on these studies.

The third study compares the addictive property of a casein-derived peptide with morphine, and it finds that although both occupy the similar receptor sites, the casein peptide did not produce an addictive response whereas the morphine did.

The fourth and fifth studies show that opioid peptides actually exert strong development and regeneration of nervous tissue - they stimulate nerve growth. May have something to do with all this improvement some people see when they put dairy and whole grains back into their diets with enzymes.

The studies 6 through 12 show the antibacterial properties in casein. The current investigation and finding of different caseins and content by cows also supports this.see Cow Milk Types

The point of this is if the yogurt/cheese is working out for you, don't worry about the casein and feel all guilty. There is much to support its beneficial properties as well.

Biologically active peptides derived from milk proteins are inactive within the sequence of the precursor proteins but can be released by enzymatic proteolysis. Based on structure-activity studies, peptides with a defined bioactivity show common structural features.
Moreover, many milk protein-derived peptides reveal multifunctional bioactivities. Bioactive peptide fragments originating from milk proteins should be taken into account as potential modulators of various regulatory processes in the body.

Opioid peptides are opioid receptor ligands with agonistic or antagonistic activities. Angiotensin converting enzyme (ACE) inhibitory peptides can exert an antihypertensive effect. Immunomodulating casein peptides have been found to stimulate the proliferation of human lymphocytes and the phagocytic activities of macrophages. Antimicrobial peptides have been shown to kill sensitive microorganisms. Antithrombotic peptides inhibit the fibrinogen binding to a specific receptor region on the platelet surface and also inhibit aggregation of platelets.

Casein phosphopeptides can form soluble organophosphate salts and may function as carriers for different minerals, especially calcium. In relation to their mode of action, bioactive peptides may reach target sites (e.g., receptors, enzymes) at the luminal side of the intestinal tract or after absorption, in peripheral organs. The physiological significance of bioactive peptides as exogenous regulatory substances is not yet fully understood. Nevertheless, several bioactive peptides derived from milk proteins have been shown to exert beneficial physiological effects. Milk-derived peptides were already produced on an industrial scale and as a consequence these peptides have been considered for application both as dietary supplements in "functional foods" and as drugs.

The first part of the present review is focused on structural aspects concerning the so far studied casein fractions of various origins: they are compared to the four classical major bovine caseins (alpha s1-, alpha s2-, beta- and kappa). The calcium-sensitive casein
fractions are always phosphorylated whereas kappa-caseins are glycosylated. The study of the casein genes showed that the calcium- sensitive caseins diverged from a common ancestral gene and during the evolution, intergenic and intragenic duplications occurred. The considerable conservation of the phosphorylation sites emphasizes the importance of phosphorylated residues for the function of caseins, i.e. the formation of micelles and the binding of Ca2+. In kappa-caseins all the prosthetic sugar groups are linked by O- glycosidic linkages: their number varies from 0 to 5 in bovine kappa- casein and up to 10 in human kappa-casein. The structures of the known kappa-casein carbohydrate moieties are described. Finally the milk clotting process (interaction kappa-casein/chymosin) is
compared to the blood clotting process (interaction fibrinogen/thrombin): a large number of similarities could be noted between both clotting phenomena. The second part of the review is devoted to the study of short casein peptides endowed with various biological activities. Some of them behaved as immunomodulators or casomorphins or angiotensin I converting enzyme inhibitors; others demonstrated an effect on platelet functions.

A 'strategic zone' containing immunostimulating and opioid peptides could be located in cow and human beta-caseins. Furthermore bitter peptides, emulsifying peptides, calcium absorption enhancing peptides, chymosin-inhibiting peptides, have also been described and several further properties have been attributed to the kappa-caseinoglycopeptide; two tetrasaccharides isolated from the latter possess blood group activities. In conclusion caseins, the main milk proteins, should not only be considered as a nutriment but as a possible source of biologically active components. If, in the future, some of the discussed active peptides cannot be characterized in vivo, they can all, nevertheless, be synthesized and used either as food additives or in pharmacology.

Eighty-four male rats were tested to determine their preference for one of two distinctive places in an experimental space. After an initial determination of place preference, rats were assigned to six groups. They were then subjected to procedures to condition a place
preference using doses of beta-casomorphin, a standard dose of morphine, or placebo. Subsequently, rats were tested for place preferences. No evidence emerged indicating that injections of beta- casomorphin conditioned a place preference, but evidence indicated
that morphine conditioned a place preference. Consequently, systemically administered beta-casomorphin has very limited or no reinforcing properties similar to those of morphine. Ingestion of milk products containing beta-casomorphin is not likely to become the focus of an addiction.

Beta-CM-4 amide (morphiceptin) and des-Tyr'-beta-CM-7 also exhibited the similar promoting effects, although their effects were very weak. The promoting effect of beta-CM-5 was prevented by co- administration of naloxone, or pretreatment with pertussis toxin. These results suggest that the neuronal survival-promoting effects of beta-CMs might be mediated through opioid receptors coupled to G proteins.

It was shown that opioid peptides stimulate nervous tissue growth in culture in the rat, which manifests itself in augmented outgrowth of neurites from explants and in an increase in the number of glial and fibroblast-like cells in the growth zone. The effects of opioid peptides ([Leu]- and [Met]-enkephalins, beta- and gamma-endorphins and some synthetic analogues of [Leu]-enkephalin) on the growth of organotypic cultures of rat sympathetic and dorsal root ganglia and spinal cord were investigated.

Neurite outgrowth, cell composition, and size of the growth zone as well as the dynamics of its formation were estimated. Changes in the survival of neurons in dorsal root ganglion cultures were determined. The experiments were performed with living cultures as well as with fixed preparations. In experiments with sympathetic ganglia, it was demonstrated that a significant growth-promoting effect is exerted by peptides taken at concentrations of 10(-8) M to 10(-14) M. Naloxone does not eliminate the effects of peptides, but stimulates the growth at 10(-5) M to 10(-7) M. Studies with spinal cord revealed that naloxone (10(-6) M) enhances the response to [Leu]-enkephalin (10(-9) M). The survival of dorsal root ganglion neurons under the influence of a [leu]-enkephalin analog (10(-9) M) exceeds control values by pproximately two to four times.

Thus, opioid peptides were shown to exert a strong growth-promoting effect on nervous tissue in culture. This effect is dual: in neurons the peptides stimulate the outgrowth of neurites and their survival, while in glial cells they change the rate of their migration and,
probably, their proliferation. It is suggested that opioid peptides, besides their already established functions, may play a role in the development and regeneration of nervous tissue.

These following abstracts indicate that certain peptides from casein have antibacterial properties (there are more, I just retrieved these). This leads to the question: Does going dairy/casein-free make a child more susceptible to gut bacterial infection? If so, then enzymes or SCD may certainly be a better alternative than eliminating these foods if possible. Even more so as the extra enzymes may produce more of those beneficial anti-bacterial peptides, or free up the anti-bacterial elements so they can be of use? In the case of SCD approved yogurt, the probiotic cultures would be degrading the casein (as do supplemental enzymes) and so producing the same effect. Yogurt has been used as a health-promoting food for years.

It also further explains the dramatic improvement many people see when they use DPP IV containing enzyme products and put dairy back into the diet. Additionally, the SCD strongly advocates using the special dairy yogurt and some cheeses as the real pro-active healing factor needed to heal the gut and restore proper microbial health.

Acid-precipitated rabbit 'whole casein' was digested by trypsin, chymotrypsin, pepsin, and clostripain to screen for possible peptides with antibacterial properties. The peptide fragments were separated by reversed-phase chromatography. The collected fractions were pooled and their antibacterial properties tested against Escherichia coli, Bacillus subtilis and Staphylococcus lentus. Three antibacterial peptide fragments derived from tryptic digestion of rabbit casein were isolated and identified. Their sequences were found as follows: HVEQLLR (residues 50-56 of beta-casein), ILPFIQSLFPFAER (residues 64-77 of beta-casein), and FHLGHLK (residues 19-25 of alpha(s1)-casein). The three peptides were synthesized and found to exert antibacterial effect against gram positive bacteria only. Proteolytic digestion of rabbit casein by chymotrypsin, pepsin and clostripain yielded several peptide fragments with antibacterial activity. Since antibiotic peptides can be released from casein during the digestion of milk proteins, our results suggest a possible antibacterial function of rabbit caseins. It is conceivable that antibacterial peptides can be generated by endopeptidases of the mammalian gastrointestinal tract possibly providing protection for new-born rabbits against aggression of micro-organisms.

Two distinct domains with antibacterial activity were isolated from a peptic hydrolysate of bovine alpha(s2)-casein. The digested alpha(s2)-casein was fractionated by cation-exchange chromatography, after which the peptides in the two active fractions obtained were separated by high-performance liquid chromatography and sequenced by electrospray-ionization tandem mass spectrometry. The major component in each active fraction, f(183-207) and f(164-179), was further purified and the antibacterial activity of these components was tested against several microorganisms. Depending on the target bacterial strain, these peptides exhibited minimum inhibitory concentrations between 8 and 99 microM. Peptide f(183-207) exhibited a consistently higher antibacterial activity than f(164-179), although both peptides showed a comparable hemolytic effect. A method of in situ enzymatic hydrolysis on a cation-exchange membrane to obtain a fraction enriched in the most active antibacterial domain is presented. The antibacterial and hemolytic activities are discussed in relation to the structure and hydrophobicity of the peptides.

Caseinomacropeptide (CMP) is a heterogeneous C-terminal fragment (residues 106 to 169) of bovine milk kappa-casein composed of glycosylated and phosphorylated forms of different genetic variants. We have demonstrated that CMP has growth-inhibitory activity against the oral opportunistic pathogens Streptococcus mutans and Porphyromonas gingivalis and against Escherichia coli. CMP was fractionated using reversed-phase high-performance liquid chromatography (RP-HPLC), and each fraction was tested for activity against S. mutans in a 96-well-plate broth assay. Fractions were characterized by N-terminal sequence analysis and mass spectrometry. The active form of CMP was shown to be the nonglycosylated, phosphorylated kappa-casein (residues 106 to 169) [kappa-casein(106--169)], which we have designated kappacin. Endoproteinase Glu-C was used to hydrolyze CMP, and the generated peptides were separated using RP-HPLC and gel filtration-HPLC and then tested for activity against S. mutans. The peptide Ser(P)(149)kappa-casein-A(138--158) was the only peptide generated by endoproteinase Glu-C digestion that exhibited growth-inhibitory activity. Peptides corresponding to the sequences of the inhibitory peptide Ser(P)(149)kappa-casein-A(138--158) and its nonphosphorylated counterpart kappa-casein-A(138--158) were chemically synthesized and tested for antibacterial activity. The synthetic Ser(P)(149) kappa-casein-A(138--158) displayed growth-inhibitory activity against S. mutans (MIC, 59 microg/ml [26 microM]). The nonphosphorylated peptide, however, did not inhibit growth at the concentrations tested, indicating that phosphorylation is essential for activity.

Proteolytic digestion of bovine beta-lactoglobulin by trypsin yielded four peptide fragments with bactericidal activity. The peptides were isolated and their sequences were found as follows: VAGTWY (residues 15-20), AASDISLLDAQSAPLR (residues 25-40), IPAVFK (residues 78-83) and VLVLDTDYK (residues 92-100). The four peptides were synthesized and found to exert bactericidal effects against the Gram-positive bacteria only. In order to understand the structural requirements for antibacterial activity, the amino acid sequence of the peptide VLVLDTDYK was modified. The replacement of the Asp (98) residue by Arg and the addition of a Lys residue at the C-terminus yielded the peptide VLVLDTRYKK which enlarged the bactericidal activity spectrum to the Gram-negative bacteria Escherichia coli and Bordetella bronchiseptica and significantly reduced the antibacterial capacity of the peptide toward Bacillus subtilis. By data base searches with the sequence VLVLDTRYKK a high homology was found with the peptide VLVATLRYKK (residues 55-64) of human blue-sensitive opsin, the protein of the blue pigment responsible for color vision. A peptide with this sequence was synthesized and assayed for bactericidal activity. VLVATLRYKK was strongly active against all the bacterial strains tested. Our results suggest a possible antimicrobial function of beta-lactoglobulin after its partial digestion by endopeptidases of the pancreas and show moreover that small targeted modifications in the sequence of beta-lactoglobulin could be useful to increase its antimicrobial function.

Here we report the isolation and characterization of an antibacterial peptide from bovine milk inhibiting the growth of Escherichia coli, and Staphylococcus carnosus. The primary structure of the peptide was revealed as a 39-amino-acid-containing fragment of bovine alpha s2-casein (position 165-203) by means of Edman amino acid sequencing and mass spectrometry. Since human milk does not contain any casein-alpha s2, these findings could explain the different influence of human and bovine milk on the gastrointestinal flora of the suckling.

Apart from immunoglobulin A and G antibodies and plasma cells, milk also contains antibiotic/host protective peptides that are of value not only for maintenance of its nutritional integrity but also for protection of the newborn and, possibly, protection of the lactating mother. Among the first such peptides identified with casecidin; following chymosin digestion of casein at pH 6 or 7, casecidin inhibited in vitro staphylococci, sarcina, Bacillus subtilis, Diplococcus pneumoniae and Streptococcus pyogenes. Inhibition occurred at high concentrations, in vitro, compared with commercial antibiotics, and thus interest in casecidin languished. Work with casecidin was followed by investigation of a related refined non-immunogenic product of chymosin digestion of alpha s1-casein. This product consisted of the N -terminal segment (1-23) of alpha s1-casein B, named "isracidin", and was significantly effective in vivo at concentrations that were competitive with known antibiotics, as seen in the protection of mice against lethal infection by Staphylococcus aureus strain Smith. Field trials showed that injection of isracidin into the udder gave protection against mastitis in sheep and cows. Isracidin was both therapeutic and prophylactic and responses to its therapeutic effect produced long-term immune resistance. Isracidin protected mice against Candida albicans, by stimulation of both phagocytosis and immune responses. However, like other recently described milk-derived peptides, despite its clinical value, isracidin was overlooked because of the lack of commercial interest in the 1970s and early 1980s, in host-mediated non-specific resistance as a therapeutic approach to infection. Another problem that impeded commercial interest was the isomeric variation in isracidin peptides seen on a large-scale batch production for commercial use. It is hoped that this review of previous studies of the activity of isracidin action will revive interest in milk as an antibiotic source.

Proteolytic digestion of bovine beta-lactoglobulin by trypsin yielded four peptide fragments with bactericidal activity. The peptides were isolated and their sequences were found as follows: VAGTWY (residues 15-20), AASDISLLDAQSAPLR (residues 25-40), IPAVFK (residues 78-83) and VLVLDTDYK (residues 92-100). The four peptides were synthesized and found to exert bactericidal effects against the Gram-positive bacteria only. In order to understand the structural requirements for antibacterial activity, the amino acid sequence of the peptide VLVLDTDYK was modified. The replacement of the Asp (98) residue by Arg and the addition of a Lys residue at the C-terminus yielded the peptide VLVLDTRYKK which enlarged the bactericidal activity spectrum to the Gram-negative bacteria Escherichia coli and Bordetella bronchiseptica and significantly reduced the antibacterial capacity of the peptide toward Bacillus subtilis. By data base searches with the sequence VLVLDTRYKK a high homology was found with the peptide VLVATLRYKK (residues 55-64) of human blue-sensitive opsin, the protein of the blue pigment responsible for color vision. A peptide with this sequence was synthesized and assayed for bactericidal activity. VLVATLRYKK was strongly active against all the bacterial strains tested. Our results suggest a possible antimicrobial function of beta-lactoglobulin after its partial digestion by endopeptidases of the pancreas and show moreover that small targeted modifications in the sequence of beta-lactoglobulin could be useful to increase its antimicrobial function.Study on Whole-food Dairy Effects on H. pylori

This was interesting on several levels:
- whole-food benefit greater than supplements
- effect on H. pylori (the ulcer bacteria)
- lactoferrin effects on iron
========

To investigate a potential new treatment for gastric Helicobacter pylori infection, we have examined the use of the natural antibiotic lactoferrin, found in bovine milk, for activity against Helicobacter species both in vitro and in vivo. Lactoferrin was bacteriostatic to
H. pylori when cultured at concentrations > or =0.5 mg/ml. Growth of H. pylori was not inhibited by another milk constituent, lysozyme, or by a metabolite of lactoferrin, lactoferricin B, but growth was inhibited by the iron chelator deferoxamine mesylate. Lactoferrin inhibition of growth could be reversed by addition of excess iron to
the medium. Lactoferrin in retail dairy milk was found to be more stable intragastrically than unbuffered, purified lactoferrin. Treatment of H. felis-infected mice with lactoferrin partially reversed mucosal disease manifestations. It is concluded that bovine lactoferrin has significant antimicrobial activity against Helicobacter species in vitro and in vivo. Bovine lactoferrin should be further investigated for possible use in H. pylori infections in
man.